-er a-a a-b a-c a-t aaa aab aac aad aae aaf aar aat ab- aba abb abc abd abe abf abr abt ac- aca acb acc acd ace acf acr act ad- ada adb adc add ade adf adr adt aea aeb aec aed aee aef aer aet af- afa afb afc afd afe aff afr aft ar- ara arb arc ard are arf arr art at- ata atb atc atd ate atf atr att baa bab bac bad bae baf bar bat bba bbb bbc bbd bbe bbf bbr bbt bca bcb bcc bcd bce bcf bcr bct bda bdb bdc bdd bde bdf bdr bdt be- bea beb bec bed bee bef ber bet bfa bfb bfc bfd bfe bff bfr bft bra brb brd bre brf brr brt bta btb btc btd bte btf btr btt c-- caa cab cac cad cae caf car cat cba cbb cbc cbd cbe cbf cbr cbt cca ccb ccc ccd cce ccf ccr cct cda cdb cdc cdd cde cdf cdr cdt ce- cea ceb cec ced cee cef cer cet cfa cfb cfc cfd cfe cff cfr cft cra crb crc crd cre crf crr crt cta ctb ctc ctd cte ctf ctr ctt daa dab dac dad dae daf dar dat dba dbb dbc dbd dbe dbf dbr dbt dca dcb dcc dcd dce dcf dcr dct dda ddb ddc ddd dde ddf ddr ddt de- dea deb dec ded dee def der det dfa dfb dfc dfd dfe dff dfr dft dra drb drc drd dre drr drt dta dtb dtc dtd dte dtf dtr dtt eaa eab eac ead eae eaf ear eat eba ebb ebc ebd ebe ebf ebr ebt ec- eca ecb ecc ecd ece ecf ecr ect ed- eda edb edc edd ede edf edr edt eea eeb eec eed eee eef eer eet ef- efa efb efc efd efe eff efr eft era erb erc erd ere erf err ert eta etb etc etd ete etf etr ett faa fab fac fad fae faf far fat fba fbb fbc fbd fbe fbf fbr fbt fca fcb fcc fcd fce fcf fcr fct fda fdb fdc fdd fde fdf fdr fdt fea feb fec fed fee fef fer fet ffa ffc ffd ffe fff ffr fft fra frb frc frd fre frf frr frt fta ftb ftc ftd fte ftf ftr ftt ra- raa rab rac rad rae raf rar rat rba rbb rbc rbd rbe rbf rbr rbt rca rcb rcc rcd rce rcf rcr rct rda rdb rdc rdd rde rdf rdr rdt re- rea reb rec red ree ref rer ret rfa rfb rfc rfd rfe rff rfr rft rra rrb rrc rrd rrf rrr rrt rta rtb rtc rtd rte rtf rtr rtt taa tab tac tad tae taf tar tat tba tbb tbc tbd tbe tbf tbr tbt tca tcb tcc tcd tce tcf tcr tct tda tdb tdc tdd tde tdf tdr tdt te- tea teb tec ted tee tef ter tet tfa tfb tfc tfd tfe tff tfr tft tra trb trc trd tre trf trr trt tta ttb ttc ttd tte ttf ttr ttt